The activity and stability of alkaline phosphatase in solutions of water and the fused salt ethylammonium nitrate

The fused salt ethylamonium nitrate has several properties which resemble those of the biologically important solvent water. In order to shed light on the role of solvent in determining protein structure we have examined the influence of ethylammonium nitrate on the activity and stability of the enzyme alkaline phosphatase. Significantly, although reduced enzymatic activity was observed in ethylammonium nitrate solutions up to 60% (v/v) in water, the enzyme was stable to brief exposure to solutions as high as 80% (v/v) in the fused salt.